Mechanical processes for separating tallow and lean beef from a single boneless beef supply

ABSTRACT

A method for separating fat from beef pieces containing fat. The method includes, with an apparatus, reducing the size of beef pieces containing fat when the fat is in a brittle condition into a mixture of particles that comprise predominantly fat and particles that comprise predominantly lean; and, with an apparatus, separating the fat particles from the lean particles based on color differences or size differences.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/788,232, filed Jun. 30, 2015 (now U.S. Pat. No. 10,212,960), which isa continuation of U.S. patent application Ser. No. 13/489,291, filedJun. 5, 2012 (now U.S. Pat. No. 9,167,843), both of which applicationsare incorporated herein expressly by reference in their entirety

BACKGROUND

During the process of boning a carcass, and particularly a beef carcasssuch as a steer or cow, the tallow and fat often referred to as “trim”is removed. Other “trim” is cut from primal beef portions during theslicing and disassembly process of carcasses that is required duringpreparation of small cuts for human consumption. During these processes,a significant amount of lean beef can be cut from the carcass andcarried away with the fat and/or tallow. Lean beef comprisespredominantly muscle protein, although some amounts of fat and talloware present, while fat and tallow comprise predominantly glycerides offatty acids with connective tissue and collagen and are the predominantconstituents of plant and animal fat. The lean beef content in trim maybe as high as 45% to 50% by weight, or higher. Presently, trim haslittle use except for sausage production, or alternatively the fat maybe rendered.

A need therefore exists to more efficiently separate the lower valuetallow with fat from the higher value lean beef contained in trim and tomore effectively kill, reduce, or completely remove the microbialpathogenic population and to eliminate sources of cross contaminationand recontamination, while also producing a ground beef product ofspecific fat content.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to identify key features ofthe claimed subject matter, nor is it intended to be used as an aid indetermining the scope of the claimed subject matter.

Disclosed are methods relating to the reduction in the tallow contentand/or the separation of tallow and/or fat from materials, particularlyfor foods used for human consumption, including fresh, uncooked meats,and in particular beef. Applicant has made numerous contributions to theprocessing of beef, and in particular to the separation of fat from beefto produce beef products having a desired content of fat, includingprocesses that perform decontamination of the beef with such separation.The following applications are expressly incorporated herein byreference in their entirety: U.S. application Ser. No. 13/024,965, filedon Feb. 10, 2011; Ser. No. 12/968,045, filed on Dec. 14, 2010; Ser. No.12/520,802, filed on Jan. 12, 2010; Ser. No. 13/024,178, filed on Feb.9, 2011; Ser. No. 11/720,594, filed on Apr. 30, 2009; Ser. No.12/697,592, filed on Feb. 1, 2010; Ser. No. 13/422,740, filed on Mar.16, 2012; Ser. No. 13/355,953, filed on Jan. 23, 2012; Ser. No.13/324,744, filed on Dec. 13, 2011; and Provisional Application Nos.61/595,537, filed on Feb. 6, 2012; and 61/617,511, filed on Mar. 29,2012.

Tallow comprises natural proportions of fat, collagen, and connectivetissue. Fat is a single component contained within tallow. Disclosedherein is a method and apparatus for separating lean beef from fatcontained within the lean beef component without destruction of themuscle striations or reduction to small lean particulates. The methodincludes reducing the temperature of at least the fat component of thebeef to a temperature causing solidification of the fat and to a brittlecondition so that when a crushing action is applied to thetemperature-reduced pieces of beef, the crushing force is sufficient tocause fracturing and the substantial disintegration or fragmentation orbreaking up of the fat matter into small fat particles or fragments thatreadily fall away from the lean beef, but without significantly damagingthe lean matter.

In one embodiment, a method for separating fat from beef piecescontaining fat is disclosed. The method includes, with an apparatus,reducing the size of beef pieces containing fat into a mixture of fatparticles that comprise predominantly fat and lean particles thatcomprise predominantly lean, wherein the fat particles are on averagesmaller than the lean particles, and, with an apparatus, separating thefat particles from the lean particles based on size differences betweenthe fat particles compared to the lean particles.

The beef pieces may be chilled to a temperature to render the fatbrittle, and then, crushing the beef pieces to cause the fat to breakaway from the lean as small particles.

The method may further include processing the mixture of particles in avibrating sieve.

The method may further include emulsifying the fat particles into anemulsification of oily material and solids, pasteurizing the oilymaterial and the solids, and centrifuging the emulsification to separatethe solids from the oily material.

The method may further include combining the solids with the leanparticles.

The method may further include combining the lean particles with ameasured amount of the fat particles after the fat particles have beenseparated from the lean particles.

In another embodiment, a method for separating fat from beef piecescontaining fat is disclosed. The method includes, with an apparatus,reducing the size of beef pieces containing fat into a mixture ofparticles that are one of two colors, wherein fat particles thatcomprise predominantly fat are a first of the two colors and leanparticles that comprise predominantly lean are a second of the twocolors, and, with an apparatus, separating the fat particles from thelean particles based on the fat particles being the first color, and thelean particles being the second color.

The beef pieces are chilled to a temperature to render the fat brittle,and then crushing the beef pieces to cause the fat to break away fromthe lean as particles having the first of two colors.

The method may further include scanning the mixture of particles toidentify the color of individual particles, and separating the particlesthat have a similar color.

The method may further include arranging the particles on a conveyor,scanning the particles, and removing the particles that have a similarcolor from the conveyor.

The method may further include arranging individual particles in a rowon the conveyor, and in the direction of travel of the conveyor, andremoving the particles by applying compressed gas.

The method may further include emulsifying the fat particles into anemulsification of oily material and solids, pasteurizing the oilymaterial and the solids, and centrifuging the emulsification to separatethe solids from the oily material.

The method may further include combining the solids with the leanparticles.

The method may further include combining the lean particles with ameasured amount of the fat particles after the fat particles have beenseparated from the lean particles.

A method for separating fat from beef pieces containing fat isdisclosed. The method includes, with an apparatus, reducing the size ofbeef pieces containing fat when the fat is in a brittle condition into amixture of particles that comprise predominantly fat and particles thatcomprise predominantly lean and, with an apparatus, separating the fatparticles from the lean particles based on color differences or sizedifferences.

In one embodiment, the stream of fat and lean particles that areproduced in the bond-breaking device are transferred to a vibratoryseparator. A vibratory separator can separate a portion of the fatparticles while agitating and shaking the larger lean pieces so as tocause even more fat particles to separate from the larger lean beefpieces. In this embodiment, the smallest pieces of fat that areseparated can be transferred directly to the low temperature renderingsection. A vibratory separation can include one or more sieves ofdifferent mesh size so as to separate different size particles on eachmesh. In one embodiment, the vibratory separation can have a singlesized mesh, so as to separate the smallest pieces of fat. The separationthrough the vibratory separator should be such that the fat particlesthat pass through the sieve do not contain any lean beef. In this caseany particles that are fat with any amount of beef are left in the beefstream to be separated in the buoyancy separator. The method can bepracticed with any material containing fat, not just beef, includingplants and animals.

A method is disclosed that includes preparing diced beef pieces havingbeen completely frozen to a temperature, for example, below 27 F andmost preferably to about 15 F or lower, such that the consistency of thefrozen beef pieces is hard but is not frozen to a temperature so lowthat the pieces resist crushing. The treatment comprises the applicationof a crushing force most preferably from opposing sides of the frozenbeef and in a way that traps the beef pieces between, for example, apair of horizontally opposed, counter- or co-rotating, rigid rollersthat apply a crushing force to the beef pieces, and with the rollersrotating such that when the frozen beef is dropped into the spacebetween the rollers, the space is about half the size of the diced beefpieces and the rollers rotate so as to carry the frozen beef in adownward direction. This treatment is arranged to reduce the size of thefrozen diced beef to particles wherein the frozen fat has fractured andcrumbled into smaller crumb like particles and separated from the largerpieces of lean beef. The diced beef is compressed such that the fatfractures and breaks into smaller particles that are generally smallerthan the lean component, which, due to its fibrous properties, resistsfracturing and tends to remain unaffected by the crushing force.Following crushing, the stream of beef particles comprises pieces of fatthat are substantially fatty adipose tissue with no or very littlevisible lean attached, while the lean particles are mostly larger thanthe fat particles and comprise mostly lean after the fat has fracturedinto crumbs and fallen away from the lean.

The particles can then be separated based on size owing to thedifferences in size between the particles that are predominantly fat andthe particles that are predominantly lean, or the particles can beseparated based on color owing to the differences in color between theparticles that are predominantly fat and the particles that arepredominantly lean.

The particles can be treated at any time by combining them with a fluidthat comprises filtered, clean water, or carbon dioxide and water,carbonic acid (or liquid carbon dioxide), or any suitable organic acidsuch as ascorbic acid, acetic acid, per-acetic acid, acidified sodiumchlorite. Additionally, or alternatively, the fluid may comprise analkaline agent. The fluid can be clean, potable water or other fluids ora combination of fluids with agents. Fluids may include water, or fluidcarbon dioxide, or both. The fluid may further include acids, eitherorganic or inorganic, and alkaline agents. Acids include, but are notlimited to carbonic acid (water and carbon dioxide), lactic acid,ascorbic acid, acetic acid, citric acid, peracetic acid also known asacid (CH₃CO₃H). Alkalinity of the fluid may be raised by adding analkali substance, such as ammonia, ammonium hydroxide, sodium hydroxide,potassium hydroxide, calcium hydroxide, tri-sodium phosphate, and anyother suitable alkali. Additives such as sodium chloride, sodiumchlorite, and sodium hydroxide may be added, which can be followed byaddition of a suitable acid (to provide acidified sodium chlorite).

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and attendant advantages will become more readilyappreciated as the same become better understood by reference to thefollowing detailed description, when taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 2A is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 2B is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 3 is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 4 is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 4 is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 5 is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 6 is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 7 is a schematic illustration of a process for the separation oflean beef from boneless beef containing lean beef and tallow;

FIG. 8 is a schematic illustration of apparatus for the treatment oflean beef with supercritical carbon dioxide; and

FIG. 9 is a schematic illustration of a process for the treatment oflean beef with supercritical carbon dioxide.

DETAILED DESCRIPTION

The term “fat” as used herein can mean fat and tallow when used inreference to animal matter. Throughout the description “beef” may beused as a representative material that can be used in the disclosedmethods. However, it is to be appreciated that the disclosed methods canbe practiced not only on beef, but on any meat, such as from poultry,pork, seafood, and the like.

The disclosed method is a process for the processing of beef and,specifically, a process for separating lean beef and fat from bonelessbeef and producing a product of specified fat content, and treating theproduct to deactivate and/or destroy pathogens. However, the beef neednot be boneless. In one embodiment, beef with bone fragments may also beprocessed in accordance with the disclosure.

From the description herein, a method for producing a lean beef productis disclosed. The method includes: reducing the size of beef intoparticles, wherein the particles are either predominantly fat particlesor predominantly lean particles; and separating the fat particles andthe lean particles based on a size or color difference. The method mayfurther include emulsifying the fat particles into an emulsification ofoily material and solids, pasteurizing the oily material, andcentrifuging the emulsification to separate solids from the oilymaterial. The method may further include combining the solids with thelean particles. The method may further include combining the leanparticles with a measured amount of the fat particles, after the fatparticles have been separated from the lean particles. The method mayfurther include treating the lean particles under reduced pressure toadjust water content and lower the temperature of the beef product toproduce a controlled water content beef product. The method may furtherinclude chilling the beef to a temperature at which the fat will breakoff from lean beef through application of pressure and applying pressureto break off fat from lean and produce the particles that are eitherpredominantly fat particles or predominantly lean particles.

FIG. 1 illustrates the first steps in the process of separating the leanbeef from animal matter that is a combination of fat and lean matter. Arepresentative animal matter may be high fat trim byproduct from beefslaughterhouses. Generally, the animal matter is any boneless beef. Inone embodiment, the source materials can comprise a combination of whatis commonly known as 50's and 65's boneless beef, or any other suitableboneless beef. However, in other embodiments, the beef may combine boneand cartilage. All materials coming in contact with the boneless beef orany parts thereof, such as lean beef and fat are made from food gradematerials, such as stainless steel and suitable polymers, such as nylon,polyethylene, polypropylene, and the like. Furthermore processingequipment may be housed in an enclosed building within a cooledenvironment and, kept at a temperature near the freezing point of water.Also, instrumentation, such as temperature, level, pressure, flow,density, and mass meters, is provided where necessary to provide statusof and/or maintain control of the product through the many components ofthe system.

The boneless beef, which may include sizable chunks, is loaded ontohopper 102. Hopper 102 represents a vat dumper that may unload anyquantity of animal matter containing fat and lean, such as for example,the unloading of containers of approximately 2,000 lb of beef followedby size reduction equipment, such as slicing device 104. From hopper102, the beef is fed by gravity to a slicer 104. The slicing device 104is designed to slice and dice the beef and reduce beef to a size, forexample, of about 1 inch in cross section by 2 inches or less. While notlimiting, the small pieces are size reduced to approximately not morethan about 1 inch wide and 2 inches long strips or 2 inch cubes. Theindividual beef pieces of diced beef may still contain an amount of fatand an amount of lean. Slicing device 104 provides a steady flow of beefpieces to inclined conveyor 106.

The sliced and diced beef pieces continue along the inclined conveyor106, and are delivered to the entry of a chilling tunnel 108. Thechilling tunnel 108 is for chilling the beef to a temperature at whichthe fat will break off from lean beef through application of pressurethat breaks off fat from lean and produces particles that are eitherpredominantly fat particles or predominantly lean particles. Processingof the diced beef pieces through the chilling tunnel 108 results indifferences in temperature between the fat and the lean matter in eachof the individual beef particles, such that the fat is at a temperaturethat renders the fat brittle and prone to breaking, and can be separatedfrom the lean by the application of pressure, similar to a crushingforce that can break free of the lean matter, and the lean is at atemperature that is pliable and does not result in the lean matterbreaking free through the same application of pressure. However, thelean matter is chilled to a temperature at which water within the leanmatter can freeze and expand, thus, reducing the density of such leanmatter. For example, in one embodiment, the temperature of the beefpieces should be not more than, for example, 29° F. and not less than 0°F., or for example, about 15° F. to about 24° F.

The input temperature of the beef particles to the tunnel 108 may beabout 32° F. to 40° F., but preferably about 32° F. The temperature ofthe beef before the tunnel freezer 108 may be controlled, in general, byadjusting the temperature of the room in which the beef is being diced.Owing to the differences of heat transfer between fat and lean in eachbeef piece and respective amounts of water in lean versus fat matter,the chilling tunnel 108 results in different temperatures of fat andlean within each beef piece.

It has been realized that the temperature of the individual pieces thatexit the chilling tunnel 108 is not uniform throughout the particles.Because of the different heat transfer rates of fat and lean as well asthe different percentages of water within lean and fat, the temperatureof the lean will be higher than the temperature of the fat, even of thesame piece. The temperature reduction is carried out to result in leanmatter that remains flexible due to the cohesive properties of muscletissue, while the fat is cooler at the surface and is in a brittle andfriable condition due to the lower temperature. However, because thelean contains greater amounts of water than fat, the water is frozen orpartially frozen.

In one embodiment, flooding the tunnel 108 enclosure with 100% carbondioxide gas displacing what would otherwise be air is advantageous. Inthis way, carbon dioxide gas can be recycled through evaporators.Another purpose in the use of carbon dioxide is to displace air (andtherefore atmospheric oxygen), thereby inhibiting the formation ofoxymyoglobin from the deoxymyoglobin exposed at the cut lean surfaces ofeach dice or beef particle when diced or sliced.

The temperature of the quickly frozen beef particles when exiting thetunnel 108 is controlled such that lean matter comprising substantiallymuscle striations, will freeze the water and all naturally fluids. Waterrepresents about 70% of lean matter, and thus the freezing and expansionof water when frozen contributes a significant increase in volume with acorresponding decrease in density of the lean matter. The beef piecesare in a solid phase but in such a way that the physical characteristicsand properties of the lean matter is pliable and “rubbery” in texture,while the fat matter is friable such that it fractures when subjected tocompressive and twisting actions and will crumble readily into smallparticles and be freed from the lean matter. The temperature to whichthe beef pieces are reduced needs to alter the physical condition of thebeef pieces so as to facilitate the flexing of the muscle striations ofthe lean matter without causing it to fracture and break into smallerpieces, while simultaneously rendering the fat matter friable such thatit will fracture, crumble, and break into smaller separate particles. Inthis way, the friable fat having broken away from the lean when it isflexed, crushed, bent, or twisted thereby reduces the fat matter intosmall separated particles. Hence, these are referred to herein as “fatparticles.” The beef pieces remaining after fat is broken off arerelatively larger comprising mostly lean matter (because they aregenerally not broken into small particles). Hence, these are referred toherein as lean particles. The change in physical breakdown of the beefparticles into two types of particles is caused by lowering thetemperature thereof followed by physical disruption of the bond, whichfixes the fat and lean matter together in an attached state and resultsin a size difference between the larger lean particles compared tosmaller fat particles.

It has been found that reducing the temperature of the beef pieces withfat to a range of, for example, between less than 29° F. and above 26°F. will facilitate separation by providing friable fat fracturespermitting the fat to crumble into small particles, leaving the lean aslarger particles.

The chiller 108 may be a cryogenic freezer using nitrogen or carbondioxide as the refrigerant, such that upon transfer out of the chiller108 (or other style of freezer) the temperature of the fat (at itssurface) is lower than the temperature of the lean in each particle orseparate piece of beef. In one embodiment, the beef particles aretemperature reduced by transfer through chiller 108 such that thesurface temperature of the fat matter is lower (approximately 5° F.)than the surface temperature of the lean matter, which is shown to beabout 29° F., immediately following discharge from the freezer. Thetemperature at the surface of fat may be at about 5° F. or less and upto 10° F. or more such that it can be friable and crumble uponapplication of pressure, while the temperature of the lean may be 16° F.to about 34° F., for example, or alternatively below 29° F., which makesthe lean flexible and not frozen into a “rock-hard” conditionimmediately after removal from the freezing process.

The temperature reduced beef pieces can then be, without storing incontainers or otherwise that could allow temperature equilibration ofthe fat and the lean matter so as to become less than rigid, transferredthrough the bond breaking process during which the beef pieces are“flexed” or bent by distortion and partially crushed as they aretransferred between, for example, a pair (two) of parallel rollersmanufactured from any suitable stainless steel such SS316 or SS304grades, but wherein the beef pieces are not completely flattened aswould occur if placed on a hard surface and rolled upon with a veryheavy roller (steam/road roller, for example). This bond-breakingcompression process is intended to cause breakage of the friable fatmatter into smaller pieces of, in the majority of instances,approximately 100% fatty adipose tissue (fat) and smaller than the fatmatter was before transfer through the bond breaking process and muchmore so than the lean matter, which remains in most cases intact butwithout any more than about 10% fat or less, remaining attached to themajority of lean matter after transfer through the bond breakingprocess. In other words, the fat in the beef pieces will “crumble,”fracture, and break into small pieces and separate from the lean in acontinuous stream of what becomes small (smaller than before transferthrough the crushing process) fat particles, and the remains are leanparticles that still comprise some fat but are approximately more than90% lean beef.

At the exit of the chilling tunnel 108, the temperature-reduced beefpieces are crushed between rollers in the bond-breaking device 110. Thebond-breaking device is for reducing the size of beef into particles,wherein the beef pieces are reduced to particles are eitherpredominantly fat particles or predominantly lean particles.Bond-breaking device 110 includes one or more pairs of opposed rollers,wherein teeth are disposed along the longitudinal direction of eachopposed roller. Each individual teeth can run the length of the roller.The intermeshing teeth are in close, but not touching proximity with theteeth of the opposed rollers. The diced and chilled beef pieces leavingthe tunnel chiller 110 are deposited by gravity into the gap between therollers of the bond-breaking device 110. Processing in the bond-breakingdevice 110 results in the liberation of the fat from the beef pieces,thereby resulting in fat particles and lean beef particles, thatformerly comprised the fat particles. Rollers that contact the beefpieces can be smooth or comprise teeth extending the length of theroller. The gap between opposing teeth can be determined based on thesize of the fat particles that come from the outlet of the bond-breakingdevice 110. If the fat particles are too large, the spacing between theopposed rollers can be decreased to reduce the size of fat particles. Ifthe fat particles are too small and/or lean is combined with the fat,then the spacing of the intermeshing teeth can be increased.

FIG. 1 shows the end view of a pair of rollers that may be used in oneembodiment of the bond breaking apparatus. A pair of shafts can bemounted in bearings (not shown) with a timing belt drive arranged torotate two pairs of rollers in opposite directions. The distance betweenthe perpendicular centerline of each roller is held in a selectedposition such that protrusions and recesses in the opposite rollers areadjacent to each other as the rollers rotate and provide a gap.

The length of any protrusion can be less than the length of any recesssuch that the distance between the rollers provides a clamping forcethat can be applied to the beef pieces transferred therebetween but nodamage such as cutting the beef occurs. All corners are radiusedheavily, and this further limits the capacity of the rollers to damagethe beef product by cutting while performing crushing to liberate thefriable fat matter from the beef pieces, leaving mostly lean matter andlittle fat matter on the beef pieces.

The temperature of the individual beef pieces is controlled such thatthe lean matter of the beef piece will remain flexible and not be proneto breakage or shattering, while the fat matter is brittle and friableand prone to breakage and will fracture and shatter into smallparticles. In one embodiment, the bond breaking compression deviceincludes intermeshing teeth, either on opposed rollers, or on top andbottom threads running parallel in a continuous manner. The spacing ofthe teeth can be determined based on the size of the fat particles thatare shattered coming from the outlet of the bond breaking compressiondevice. If the fat particles are too large, the spacing between theteeth can be decreased to reduce the size of fat particles. If the fatparticles are too small and/or lean is combined with the fat, then thespacing of the intermeshing teeth can be increased.

In one embodiment, the fat particles and the lean beef particles exitthe bond-breaking device 110 and are deposited to an enclosed screwconveyor 112, which is shown on FIGS. 2A and 2B. FIG. 2A show twoalternatives for separating the fat particles from the lean particlesbased on size differences, or color differences.

In the embodiment of FIG. 2A, the liberated fat particles and the largerlean particles may be deposited onto a vibratory sieve 400 with a meshscreen having holes large enough for the fat particles to pass through,but not the larger lean beef particles. The size of holes of the meshscreen may be selected having smaller holes to retain more of the fatparticles with the lean particles and thus have a relatively high fatproduct, and the size of the holes of the mesh screen may be selectedhaving larger holes to allow more, if not most or all, of the fatparticles to pass through, and very little fat, if any, remains with thelean particles to produce a relatively low fat product.

A vibratory sieve is an apparatus that can separate particles ofdifferent sizes by allowing the smaller particles to pass through a meshscreen of a particular size, while the mesh screen does not allow thelarger particles size to pass through. The disclosed method of producingthe fat particles results in relatively smaller fat particles, comparedto particles that comprise mostly lean beef. In the disclosed method,different particle sizes from fat-containing beef pieces are produced,and, further, the particle sizes produced correspond to whether thematerial is fat or lean. In the disclosed method, fat particles areproduced that are, on the whole, smaller than the particles comprisingmostly lean beef. The vibratory sieve can separate by a combination ofmotions that result in stratification of the smaller particles in onestratum, and the larger particles in a different stratum. The smallerparticles are allowed to pass through the sieve and are collected in oneoutlet and are sent to the fat vessels 148A, B in FIG. 3. The leanparticles are collected in a second outlet and are sent to the leanvessels 144A,B in FIG. 3 While one representative embodiment of a sieveto separate according to size difference is illustrated and described,it should be appreciated that other methods and apparatus may be usedfor separation small particles from a mixture of small and largeparticles.

FIG. 2B is an illustration of an another embodiment for separation offat particles and lean particles. The mixture of fat particles and leanparticles are deposited onto a conveyer 402. In one embodiment, theparticles can be deposited linearly in a row along the direction oftravel of the conveyor to form a row of individually arranged particles.The purpose for this will become apparent. The particles then passunderneath the field of vision of a camera, or other image-capturing, orvideo, apparatus 404. The images captured by the apparatus 404 can beanalyzed via the use of a processor 406. The processor 406 is able todetermine the color of the particle and, based on the color, make adetermination whether the particle should be classified as a fatparticle or a lean particle. Video image analysis and classification ofanimal carcasses is known. However, the disclosed method of producingfat particles results in fat particles that are essentially of a singleuniform color (i.e., the fat particles do not comprise visual lean redmeat), and therefore the color of the entire fat particle can begenerally viewed as uniform. The color of particles that comprise mostlylean beef is also generally uniform throughout the entire particle. Suchlean particles being the color of freshly cut lean red beef. In thedisclosed method, particles of different colors are produced fromfat-containing beef pieces, and further the particle color correspondsto whether the particle is generally essentially fat or lean matter. Inthe disclosed method, fat particles are produced that are, on the whole,a whitish or yellow color that is different from the generally red colorof particles comprising mostly lean beef. In the disclosed method, theprocessor provides a determination whether each individual particle isone of two colors, which corresponds to whether the particles is one oftwo materials (fat or lean), which makes sorting reliable and efficient.

After a determination is made whether an individual particle is fat orlean, the processor 406 can communicate with a sorting apparatus 408,such as a pneumatic device that can direct a puff of compressed air (orany other gas) onto the particle 416, (for example, a fat particle) toremove the particle 416 from the conveyor 402. The particles that areblown off the conveyor 402 are collected into a bin 412, and aretransferred to the fat vessels 148A,B in FIG. 3. A reason why theparticles may be individually aligned single file on the conveyor is toprovide a clear path for the particles to be removed, withoutinterference from other particles that should not be removed from theconveyor. However, other configurations are possible, where more thanone particle can be removed at the same time, and arranging particlessingle file may not be necessary. For example, the use of a robot with aclaw can lift particles from the conveyor when particles may bearranged, or even scattered, across the width of the conveyor. Thoseparticles that remain on the conveyor are the lean particles, forexample, and are deposited onto the bin 410. From bin 410, the leanparticles are transferred to the lean vessels 144A,B in FIG. 3.

To determine which particles are to be removed, the processor 408 mayalso keep track of particles. In one embodiment, keeping track ofparticles may be by way of a set of cameras, or video apparatus, thatcount the particles that pass underneath the classification imagingcamera 404. For example, a first camera positioned so as to count aparticle as it passes underneath the imaging camera 404, would identifythe order of the particles, simultaneously as the processor 406identifies it as being either a fat particle or a lean particle. Forexample, keeping track can be as simple as assigning a number, such as1, 2, 3, and so on. If the imaging camera 404 classifies particle number3 as needing to be removed, a second counting camera positioned down theconveyor from the imaging camera can similarly count the particles, andwhen particle number 3 is detected, the sorting apparatus 408 isactivated to remove particle number 3.

The fat in vessels 148A and 148B may contain approximately 15% water and10% to 15% by weight protein. This protein may be recovered in the lowtemperature rendering section of FIG. 4, and the recovered solids arereintroduced to the lean beef in vessels 144A,B.

Vessels 148A and 148B rest on load cells that determine when a vessel isfilled to capacity. Only one vessel 148B or 148B is generally loadedwith material at a time. When the vessel reaches capacity, a transfervalve 170 may automatically switch to the empty vessel. While one vessel148B or 148B is being filled, the standby vessel may be emptied ofmaterial to be ready to receive material when the other vessel is filledto capacity. The bottom outlets of the vessels 148B and 148B share acommon outlet to a pump 174. Pump 174 transfers the fat particles to alow temperature rendering system illustrated in FIG. 4, furtherdescribed below.

Prior to or after the fat and lean particles are sent to theirrespective vessels, a process may be conducted to combine the leanparticles with a measured amount of the fat particles, after the fatparticles have been separated from the lean particles. The fat contentof the lean particles and the fat particles can be measured via the useof Coriolis meters, and addition of fat can be undertaken to raise thefat content of the lean product stream to a desired level. This can bedone by transferring fat from the vessels 148A,B to the lean productstream as it is being transferred into or out of vessels 144A,B. The fatcontent of the lean product stream may then again be measured to verifythe level of fat.

As described in connection with FIG. 3 above, the fat particles from thefat reservoir vessels 148 a and 148 b are transferred to a lowtemperature rendering system. This system is illustrated in FIG. 4. Thefat reservoir vessels 148A and 148B are emptied by transferring the fatparticles via the conduit 198. The conduit 198 leads into a variablespeed emulsifier 158. Emulsifier 158 applies a shear force on the fatparticles, generally by the application of a sharp rotating edge. Theshear action breaks the walls of any fat cells to produce anemulsification of oily material and solids. The fat material is reducedto an emulsion, which is then transferred via pump 200 to one side of aplate heat exchanger 161. Recirculating water is metered and temperaturecontrolled to the plate heat exchanger 161 via conduit 162. The heatedfat emulsification leaving the plate heat exchanger 161 through conduit202 is approximately 108° F. to 180° F. The oily material may bepasteurized by the plate heat exchanger 161.

The fat emulsification transferred through conduit 202 enters a Votatorscraped surface heat exchanger 204. In scraped surface heat exchange204, the fat emulsification is further heated to approximately 160 to190° F. The fat emulsification from scraped surface heat exchanger 204is then transferred via conduit 208 to a decanter centrifuge 164.Decanter centrifuge 164 separates solids from the fat emulsification.The solids leaving the decanter centrifuge 164 may be considered leanfinely textured beef (LFTB). This LFTB includes connective tissue,water, cell walls, and protein. This LFTB may be considered lean beefand typically has some fat with it. The solids (LFTB) leaving thedecanter centrifuge 164 via outlet 210 may be combined with the leanparticles in the lean reservoir vessels 148A and 148B. Alternatively,the solids (LFTB) may be considered a separate product.

The decanter centrifuge 164 separates the fat emulsification via outlet212. The fat emulsification at this point may be tallow, with the solidsremoved. The tallow removed via conduit 212 is pumped via pump 214 intoconduit 166. Conduit 166 transfers the fat emulsification into a secondplate heat exchanger 168. The second plate heat exchanger 168 heats thefat emulsification to approximately 160 to 190° F., and in any event thetemperature is raised to pasteurize the tallow. Hot water is provided tothe second plate heat exchanger 168 via the hot water recirculationsystem via conduit 216. The water is returned from the plate heatexchanger 168 to the hot water recirculation system. The tallow leavesthe second plate heat exchanger 168 via conduit 170. Conduit 170transfers the heated tallow into the disk centrifuge 172.

The disk centrifuge 172 separates further solids via outlet 218. Solidsseparated by the disk centrifuge 172 and transferred via conduit 218 arepumped via pump 220 and combined with the solids (LFTB) from thedecanter centrifuge 164. The combined solids may be reintroduced intothe reservoir vessels 144A and 144B containing the lean particles.Alternatively, the solids (LFTB) are packaged and considered a separateproduct from the lean beef. Water is separated from the disk centrifuge172 via conduit 224.

The emulsifier 158 is used to break cell walls of fat to release oil.The solids including the cell walls are transferred with the solids, andwill separate in the decanter centrifuge 164 and/or the disk centrifuge172. The oil, which is essentially tallow, is separated from the diskcentrifuge via conduit 222 and sent to oil storage vessels 230 a,b ofFIG. 6. The oil thus produced has many uses. Being food grade, the oilmay be used in the manufacture of any type of food, such as snacks, usedas commercial cooking oil, as a flavor additive, or any otherapplication of a food-grade oil. Additionally or alternatively, the oilmay be used in the production of biodiesel.

Referring to FIG. 6, the oil separated from disk centrifuge 172 in FIG.4 is transferred via conduit 222. As seen in FIG. 6, the conduit 222leads to one of two vessels 230A and 230B. The oil from conduit 222 mayenter either one of two oil storage vessels 230A or 230B. Storagevessels 230A and 230B may sit on load cells. Load cells can be used todetermine when the vessels 230A and 230B are filled to capacity. Thewater separated from the disk centrifuge 172 (FIG. 4) is transferred viaconduit 224. Conduit 224 leads to one of two vessels 232A and 232B.Vessels 232A and 232B may sit on load cells that are used to determinewhen the vessels 232A and 232B are filled to capacity. When the loadcells detect that the vessels are at capacity, a valve 242 may switchautomatically to stop filling the vessel that is at capacity and startfilling the empty vessel.

Oil storage vessels 230A and 232B may each have a capacity ofapproximately 200 gallons, while water storage vessels 232A and 232B mayhave a capacity of about 15 gallons each. The tops of the vessels 232A,232B, 230A, and 230B may all be connected at the top end thereof to acommon manifold 234. Manifold 234 may lead to carbon dioxide collection.

Vessels 230A and 230B each have an outlet at the bottom end thereof thatis combined into a conduit 238. Vessels 232A and 230B have a commonoutlet 236.

The oil being separated by the disk centrifuge 174 may have little to nowater. Accordingly, water that has been initially separated from the fatcells in the emulsification and rendering section may be returned at arate to achieve an approximately 15% by weight water content in oil fora final composition of approximately 85% by weight oil, and 15% byweight water. If water is added to the oil, the combination may betreated by a homogenizer 240 to introduce the water back into the oil.The homogenized oil/water may be used as an ingredient in many products.

The lean particles from either separation process of FIG. 2A, or 2Btravel through a Coriolis meter 165 for massflow measurement. The leanparticles are then stored in either of reservoir vessels 144A or 144B.Vessels 144A and 144B rest on load cells which determine when a vesselis filled to capacity. Only one vessel 144A or 144B is generally loadedwith material at a time. When the vessel reaches capacity, a transfervalve 172 may automatically switch to load the empty vessel. While onevessel 144A or 144B is being filled, the standby vessel may be emptiedof material to be ready to receive material when the other vessel isfilled to capacity. The bottom outlets of the vessels 144A and 144Bshare a common outlet to a pump 146. Pump 146 transfers the lean beefparticles to a vessel, such as one illustrated in FIG. 8 that is for thepurpose of treating the lean beef with supercritical carbon dioxide toreduce pathogens, and will be described later. However, other methodsfor treating the lean particles to reduce pathogens are possible. It canbe advantageous to pathogen reduce the lean beef separate from the fat,since the fat may undergo pasteurization through heating, while heatwill detrimentally affect the quality of raw beef.

Referring to FIG. 7, a method for separating fat from lean beef whileminimizing the loss of micronutrients from the lean beef is illustrated.

The method begins by introducing pieces of beef 300 into a chillingtunnel, block 302. The apparatus for performing this step is illustratedin FIG. 1. However, other apparatus are suitable. As described inassociation with FIG. 1, the purpose of the chilling tunnel is forreducing the temperature of the beef pieces to a temperature at whichthe fat can be broken off from the lean beef while the lean beef remainsessentially pliable and does not break into smaller particles. Fromblock 302, block 304 is entered.

In block 304, the beef pieces are processed by an apparatus that iscapable of breaking the bonds between fat and the lean matter. Oneembodiment of an apparatus for performing this “bond-breaking” processis illustrated in FIG. 1. However, other apparatus are suitable. Asdescribed in association with FIG. 1, the bond-breaking apparatus caninclude two sets of parallel spaced-apart rollers with or withoutintermeshing teeth and through which the beef pieces are droppedtherebetween after being temperature-reduced in the chilling tunnel.From block 304, block 306 is entered.

Block 306 is for separating the fat particles from the lean particles.Various embodiments of apparatus capable of achieving such separationare described in association with FIGS. 2A, and 2B. However, otherapparatus are suitable.

From block 306, the separated fat particles are transferred to the fatvessels, block 308. The fat vessels for weighing the fat are describedin association with FIG. 3.

From block 308, block 310 is entered. Block 310 is for rendering the fatparticles into tallow, and lean, finely textured beef. Apparatussuitable for rendering the fat particles into both tallow and lean,finely textured beef is described in association with FIG. 4. However,other apparatus is suitable.

From block 306, block 320 is also entered. Block 320 is for weighing thelean particles in vessels. Apparatus for weighing the lean particles isdescribed in association with FIG. 3. From block 320, block 318 isentered.

Block 318 is for treating the lean particles to reduce pathogens. In oneembodiment, the lean particles can be treated with carbon dioxide atsupercritical conditions, i.e., above the critical temperature andpressure of carbon dioxide. The separation method disclosed herein canachieve the production of diced beef having a content of approximately90% or more by weight of lean beef. Additionally, the disclosed methodcan be used to product tallow and lean, finely textured beef (LFTB) fromfat.

Referring now to FIGS. 8, and 9, an apparatus 1000 and method 400 fordecontaminating lean beef with supercritical carbon dioxide areillustrated. The apparatus 1000 is used for separately treating the beeffrom fat for pathogen deactivation.

Boneless beef, as provided after a carcass has been processed to removethe primals, when infected with Pathogens, such as E. Coli 0157:H7, willgenerally comprise a fat component which will likely include apredominant proportion of the total pathogen population while the leancomponent will likely comprise a lower pathogen population. This occursbecause pathogen contamination generally occurs due to contact with anyvector of pathogen contamination by the outer surface making contacttherewith. The outer surface of a beef carcass is generallysubstantially covered with a fat layer hence the fat component ofboneless beef and trim will often comprise the major proportion of anypathogen contamination contained with a given quantity of boneless beef.Separating the fat component from the lean component can, therefore,provide a means of dividing the pathogen population with a greaterproportion carried with the fat component and less with the lean beefcomponent. The fat component includes protein of significant value, evenafter separation from the lean component and fat with proteins can beheated to higher temperatures compared to lean beef, such as above apasteurization temperature of 160° F. and higher. However, the leancomponent cannot be heated without causing unacceptable changes in colorand composition. Therefore, the proteins contained in the fat componentcan be separated and then recombined with the lean component withoutaffecting the finished high lean content product. Furthermore, when 30's(XF's) or 50's boneless beef are separated into two streams of: (1) afat and beef proteins (including chemical lean) component; plus, (2)lean beef of approximately 90% or 93% lean content (visual lean), anopportunity to subject each stream to different pathogen deactivationtreatments is available. Most preferably, the fat stream (with proteins)can be pasteurized by elevating the temperature of the stream to above apasteurization temperature of greater than 160° F. while the heatsensitive lean stream can be most preferably treated to reduce pathogenpopulations in supercritical carbon dioxide and, according to the methoddescribed in the applicant's U.S. Pat. No. 8,101,220, to undetectablelevels while the predominantly fat stream (and any proteins) can bepasteurized thermally by increasing its temperature to greater than 160°F. or greater than 190° F. Accordingly, after separation of the leancomponent from the fat component, followed by separation of the leanstream from the fluid with which it (and the fat stream) was combinedprior to separation of fat from lean, the lean component can be immersedin supercritical carbon dioxide according to a treatment described inthe referenced '220 patent. Applicant's U.S. Pat. No. 8,101,220,entitled TREATMENT TO REDUCE MICROORGANISMS WITH CARBON DIOXIDE BYMULTIPLE PRESSURE OSCILLATIONS, which is hereby incorporated with thispatent application for all purposes, can effectively reduce pathogenpopulations to undetectable levels without affecting the appearance ofthe lean component. Separately, the fat stream, which can containsubstantial quantities of proteins, can be homogenized and thenpasteurized by heating to an elevated temperature of greater than 190°F. or at least above 160° F. or higher such as 200° F. or more, whichwill render all pathogens inactive. The heat pasteurized stream of fatand proteins is then centrifuged to separate the liquid fat (tallow)from the proteins and any remaining water. The proteins and water canthen be recombined with the lean stream without any deleterious effecton appearance of the fresh lean beef.

The apparatus 1000 and method 400 are described in applicant's U.S. Pat.No. 8,101,220. For brevity, the apparatus 1000 will not be described, asit is fully disclosed in the '220 patent, and reference may be easilymade. In general, any device that is capable of achieving the criticaltemperature and pressure of carbon dioxide is suitable. The illustrateddevice is capable of achieving such carbon dioxide critical temperatureand pressure via the use of hydraulically-activated pistons thatcompresses a space filled with carbon dioxide fluid and the lean beef.It should be noted that the apparatus 1000 may use a substantiallyincompressible fluid, such as potable water, that will not renderinedible the lean beef should a hydraulic fluid leak occur.

The apparatus 1000 can be used to destroy or render harmless virusessuch as hepatitis, malaria, tuberculosis, the SARS virus, and also theextraction of prions that may have become mixed with the lean beef. Suchprions may be the cause of BSE (bovine spongiform encephalopathy). It iswell known that in order to destroy BSE prions, they must be heated to avery high temperature and to such an extent that the molecule willchange form by decomposition or reaction with other elements orcompounds. However, such temperatures cannot be applied to food, such asboneless lean beef, and therefore the preferred means of dealing withsuch a food safety matter can occur by removal from the food stream. Inthe event that such prions are known to be present with any food, thefood product must be removed from the food chain and dealt with asrequired according to USDA regulations. However, the apparatus 1000 mayprovide a useful precautionary means of washing boneless beef portionswith supercritical carbon dioxide (carbon dioxide above the criticaltemperature and pressure) and then separating the lean beef fromfluidized extracts collected in a stream of carbon dioxide fluid.

Referring to FIG. 9, a method for treating lean beef with fluid carbondioxide, including supercritical carbon dioxide, is illustrated. Amethod in accordance with one embodiment includes introducing bonelessbeef, carbon dioxide, and, optionally, water under pressure in the rangeof 200 psig to 500 psig, or, alternatively, thereafter raising thepressure of carbon dioxide within the apparatus illustrated in FIG. 8such that when the pressure is reduced, the water that is on the surfaceof the goods will freeze, block 102. However, the reduction in pressureis controlled so that there is insubstantial freezing of the water belowthe surface.

In accordance with this embodiment, when the water freezes on thesurface of the boneless beef, wherein microorganisms may reside,needle-like ice formations of microscopic size form in a random pattern.As the freezing process of water continues, the needle-like iceformations become part of the solid ice that can form when all waterpresent is frozen solid. The needle-like ice crystal formationsperforate the microorganisms' cell walls and membranes. When the icecrystals thaw and defreeze, the perforations are left behind allowinglow pH dense carbon dioxide or supercritical carbon dioxide to enter themicroorganisms through the perforations. A pH differential of at leastabout 1 or less can detrimentally affect or damage the microorganisms,so too can the supercritical carbon dioxide solvent when it enters themicroorganisms. Furthermore, pH fluctuations of at least about 1 betweenthe inside of cells and the outside of cells can cause further damage.To cause the needle-like ice crystal formations, liquid or dense carbondioxide is in contact with the surfaces of the beef in sufficientquantities to cause freezing of the free water that is in contact withthe microorganisms. To this end, free water may be added to ensure thatall the surfaces of the beef that potentially could have beencontaminated have a thin layer of water that surrounds and is in contactwith the microorganisms. Such water later freezing and causing damage tothe microorganisms. It is intended that a feature of the apparatus nowbeing described is the capability to cause the partial freezing of waterby rapidly elevating and reducing the pressure of the water and carbondioxide with the boneless lean beef. More particularly, a reciprocatingaction of pistons in the apparatus 1000 can be arranged to cause partialfreezing of water provided therein, which is in direct contact with thesurface of the boneless beef. Such reciprocating piston movement canalso cause the flexing of the contents, and when bacteria cells areexposed to this physical action, the needle-like ice crystals can affectthe bacteria cells in a detrimental manner, such as by puncturing thecell walls. The rapid formation of needle-like ice crystalscorresponding with a pressure reduction, followed by the rapidelimination thereof, corresponding with an increase in pressure andtemperature, can provide an environment lethal to single cell pathogens.The lethality of the environment is created due to several mechanismsthat relate directly to the temperature and pressure of the carbondioxide. For example, when the pressure of carbon dioxide is lowered to,for example, 300 psig, from an existing pressure of 1000 psig at 50degrees F., the temperature of the lower pressure carbon dioxide willfall below the freezing point of water, therefore, causing ice crystalsto form, block 402. When a mixture of the appropriate proportions ofliquid phase carbon dioxide with liquid phase water and boneless beef,all held at a pressure of 1000 psig and temperature of 40 to 50 degreesF., and the pressure is reduced to, for example, from 300 to 400 psig,the temperature of the carbon dioxide will drop to below 20 degrees F.,and when sufficient carbon dioxide is present with the liquid phasewater, ice crystals will form. Ice crystals formed in this manner canhave needle-like characteristics easily capable of rupturing the cellwall of a pathogen, such as E. coli 0157:H7. Before substantial freezingof the food below the surface can occur, the pressure is rapidlyelevated to raise the temperature, block 403. The cycle can be repeatedas many times as is desired. With the apparatus 1000, the pressure ofcarbon dioxide can be oscillated, wherein the upper and lower pressurelimits are selected below the super critical phase of carbon dioxide.The lower pressure limits can be selected so as to ensure formation ofice crystals when the pressure is oscillated to a low pressure, and theupper pressure limits can be selected so that the ice crystals aresubstantially eliminated when the pressure is oscillated to a higherpressure. Such oscillation between low and high pressures can cause acorresponding oscillation of freezing and thawing temperatures. Anywater mixed in or on the surface of the goods will freeze when thetemperature at the lower selected pressure is sufficiently below thefreezing point of water, and the water will thaw when the temperature atthe higher pressure is sufficiently above the temperature at which waterwill freeze. When carbon dioxide and water are mixed together and arepresent at the surface of goods, such as meat (or fruits andvegetables), the ice crystals formed can, due to the needle-likemorphology that ice crystals so formed can create, be lethal to bacteriaby rupturing the cell walls thereof.

In another embodiment, the pressure and temperature conditions can beadjusted such that carbon dioxide, water, and boneless beef are retainedunder elevated pressure of, for example, up to, but less thanapproximately 1000 psig, such that the carbon dioxide and water reacttogether to form carbonic acid having a pH in the range of about 2 toabout 5, preferably about 3 to about 4. Alternatively, the pH can beless than 3, 4, or 5. The pH range can be about 2 to about 5, or anyvalue in between. The hydrated carbon dioxide (CO₂.H₂O), or morecorrectly H₂CO_(3,) is a defined compound having dissociated ionsrepresented by [H⁺] [HCO₃ ⁻] at 1000 psig. This condition results in alowering of the pH that affects pathogens in a detrimental manner and,if sufficiently low, can be lethal to pathogens, in particular when thepathogens have been previously detrimentally affected or injured, suchas by the puncturing of the pathogen cell wall membrane, as discussedabove. The needle-like ice crystals are capable of injuring pathogencells by puncturing the cell walls, and when this condition is followedimmediately by an elevated pressure of approximately 1000 psig, theresultant lower pH can more readily access the internal regions of thepathogen cell, thereby lowering the cell pH sufficient to cause death ofthe pathogen. The raising of the pressure to levels of about 1000 psigto cause a low pH can be affected by the apparatus 1000.

In yet another embodiment, a different set of temperature and pressureconditions can be achieved within the apparatus 1000 that affects themicroorganisms in a detrimental manner, block 406. When carbon dioxideis pressurized above about 1100 psig and heated above about 88° F. (or36° C.), i.e., the critical pressure and temperature of carbon dioxide,carbon dioxide is a supercritical fluid. Supercritical carbon dioxide isdetrimental to bacteria, such as E. coli 0157:H7, when the bacteria areexposed to a sufficient quantity of the supercritical carbon dioxide. Inthis embodiment, a blend of carbon dioxide, water, and boneless beef areprovided to the apparatus 1000. The pressure is elevated above 1056 psigat a temperature greater than 88 degrees F., i.e., greater than thesupercritical pressure and temperature of carbon dioxide. At thesupercritical conditions, the carbon dioxide possesses aggressivesolvent properties capable of dissolving lipids. The cell walls ofpathogens are constructed of a complex structure of lipids, and thesecell wall lipids will dissolve when exposed to a powerful solvent, suchas supercritical phase carbon dioxide. Supercritical pressure andtemperature can be produced before or after any one of the other sets ofconditions, discussed above, that detrimentally affect themicroorganisms. Furthermore, all three sets of conditions can besequenced in any order, as illustrated, and repeated any number oftimes, in the same, or a different sequence, or even one set ofconditions may be repeated two or more times before changing to anotherset of conditions. In other embodiments, only the supercriticalconditions need to be performed.

In summary, the apparatus 1000 can be used to provide one or moreprocedures, or any combination thereof, of varying pressure andtemperature conditions of carbon dioxide that can destroy and deactivatemicroorganisms, and can be carried out in any order and repeated as manytimes as desired. Such procedures include: (1) oscillating between lowand high pressure to cause ice crystal formation and thawing in rapidsuccession, (2) raising pressure to create a dense phase of carbondioxide with a low pH, and (3) raising pressure to create supercriticalcarbon dioxide to affect the cell wall lipids of microorganisms.

The apparatus 1000 is capable of transferring boneless lean beef througha pressure vessel and oscillating the pressure between any lowerpressure, such as about 300 psig, 350 psig, 400 psig, 450 psig, 500psig, and so on, and up to an elevated pressure of about 1100 psig orgreater, thereby causing multiple sets of circumstances to kill orreduce microorganisms, such as pathogens. Such lowering of pressureleads to temperature changes, such that at a lower pressure, icecrystals with needle-like characteristics will form, and, conversely,upon raising the pressure of carbon dioxide, a low pH acid is created atan elevated pressure of, for example, about 1000 psig and finally, byincreasing the pressure and temperature to supercritical levels above1058 psig and above 87.8 degrees F., lipid dissolving solventcharacteristics are achieved. The raising and lowering of pressure toachieve ice crystal formation, low pH, or lipid dissolving solventcharacteristics via carbon dioxide can be practiced in any order andrepeated as many time as is desired, or any set of conditions can bepracticed singly, and as many times or for a period to destroy or reducemicroorganism populations in lean beef.

The process is not limited to being performed in any particularsequence. For example, pathogen deactivation may occur after separation,or any time before then. Some steps may be omitted and substituted forone or more steps that perform the similar function or are arranged in adifferent sequence to perform the similar function. Some steps may beomitted that are merely ancillary or embraced as a subsystem of theprocess as a whole.

Referring to FIG. 5, the finishing step for lean beef product isillustrated. As discussed above, lean beef can be processed usingsupercritical carbon dioxide in one embodiment, for example. Beeftreated in the vessel 1000 of FIG. 8 is pumped to the top of vessel 150.Vessel 150 is operated under vacuum. The lean beef drops into the vessel150. Vessel 150 may sit on load cells, which are capable of determiningwhen the vessel 150 is filled to capacity. The vessel 150 is providedwith a knife valve 154 at a bottom end thereof. When filled to capacity,the vessel 150 may be emptied onto totes 156 and carried away on trucksor by rail to predetermined destinations. The vessel 150 is connected toa conduit 152 that operates under vacuum. Any remaining carbon dioxideand/or water that may flash vaporize is carried away via vacuum conduit152. Treating the lean particles under reduced pressure, such as vacuum,adjusts water content and lowers the temperature of the beef product toproduce a controlled water content beef product.

The final lean beef product may contain 8% to 10% by weight fat.However, the fat content may be continuously measured and adjusted asnecessary, for example, a controlled and measured quantity of fatparticles that are collected in the vessels 148A,B may be combined withthe lean beef product of vessels 144A,B.

The process is not limited to being performed in any particularsequence. For example, pathogen deactivation may occur after separation,or any time before then. Some steps may be omitted and substituted forone or more steps, or that perform the similar function, or are arrangedin a different sequence to perform the similar function. Some steps maybe omitted that are merely ancillary or embraced as a subsystem of theprocess as a whole.

While illustrative embodiments have been illustrated and described, itwill be appreciated that various changes can be made therein withoutdeparting from the spirit and scope of the invention.

1. A method for separating fat from beef pieces containing fat,comprising: with an apparatus, reducing the size of beef piecescontaining fat into a mixture of fat particles that comprisepredominantly fat, and lean particles that comprise predominantly lean,wherein the fat particles are on average smaller than the leanparticles; and with an apparatus, separating the fat particles from thelean particles based on size differences between the fat particlescompared to the lean particles.
 2. The method of claim 1, wherein thebeef pieces are chilled to a temperature to render the fat brittle, andthen the beef pieces are crushed to cause the fat to break away from thelean as small particles.
 3. The method of claim 1, further comprisingprocessing the mixture of particles in a vibrating sieve.
 4. The methodof claim 1, further comprising emulsifying the fat particles into anemulsification of oily material and solids, pasteurizing the oilymaterial and the solids, and centrifuging the emulsification to separatethe solids from the oily material.
 5. The method of claim 4, furthercomprising combining the solids with the lean particles.
 6. The methodof claim 1, further comprising combining the lean particles with ameasured amount of the fat particles after the fat particles have beenseparated from the lean particles.
 7. A method for separating fat frombeef pieces containing fat, comprising: with an apparatus, reducing thesize of beef pieces containing fat into a mixture of particles that areone of two colors, wherein fat particles that comprise predominantly fatare a first of the two colors, and lean particles that comprisepredominantly lean are a second of the two colors; and with anapparatus, separating the fat particles from the lean particles based onthe fat particles being the first color and the lean particles being thesecond color.
 8. The method of claim 7, wherein the beef pieces arechilled to a temperature to render the fat brittle, and then the beefpieces are crushed to cause the fat to break away into the particleshaving the first of the two colors.
 9. The method of claim 7, furthercomprising scanning the mixture of particles to identify the color ofindividual particles, and separating the particles that have a similarcolor.
 10. The method of claim 7, further comprising arranging theparticles on a conveyor, scanning the particles, and removing theparticles that have a similar color from the conveyor.
 11. The method ofclaim 7, further comprising arranging individual particles in a row onthe conveyor and in the direction of travel of the conveyor, andremoving the particles by applying compressed gas.
 12. The method ofclaim 7, further comprising emulsifying the fat particles into anemulsification of oily material and solids, pasteurizing the oilymaterial and the solids, and centrifuging the emulsification to separatethe solids from the oily material.
 13. The method of claim 12, furthercomprising combining the solids with the lean particles.
 14. The methodof claim 7, further comprising combining the lean particles with ameasured amount of the fat particles after the fat particles have beenseparated from the lean particles.
 15. A method for separating fat frombeef pieces containing fat, comprising: with an apparatus, reducing thesize of beef pieces containing fat when the fat is in a brittlecondition into a mixture of particles that comprise predominantly fatand particles that comprise predominantly lean; and with an apparatus,separating the fat particles from the lean particles based on colordifferences or size differences.